Microalgae-based biodiesel has gained widespread interest as an alternative energy source. Low-cost microalgae harvesting technologies are important for economically feasible biodiesel production. This study investigated, for the first time, the impact of adaptation period and height to diameter (H/D) ratio of a reactor on the growth and self-flocculation of microalgae, without the addition of bacteria. Six reactors were grouped into three sets of experiments, and each reactor was operated for 30 days at similar operating conditions (volume exchange ratio = 25% and settling time = 30 min). In set 1, two 8-L reactors, H5a (H/D ratio 5) and H8a (H/D ratio 8), were operated under batch operation. In set 2, reactors H5b and H8b were operated as sequential batch reactors (SBRs) without an adaptation period. In set 3, the reactors H5c and H8c were operated as SBRs with an adaptation period. The findings showed a threefold improvement in biomass productivity for the higher H/D ratio (H8c) and a reduction in biomass loss for microalgae. The H8c reactor exhibited 95% settling efficiency within 5 days, in comparison to 30 days for the H5c reactor. This study demonstrated that a higher H/D ratio and the introduction of an adaptation period in SBR operation positively influences growth and self-flocculation of enriched mixed microalgae culture.Magnetic nanostructured MnFe2O4 with different morphologies, synthesized via chemical co-precipitation and hydrothermal method, was assayed as heterogeneous Fenton catalysts. The as-prepared MnFe2O4 catalysts were thoroughly characterized by various characterization methods, such as X-ray diffraction (XRD), N2 adsorption-desorption, transmission electron microscopy (TEM), magnetic hysteresis loops, temperature-programmed reduction (TPR), and X-ray photoelectron spectroscopy (XPS). The catalytic activity of MnFe2O4 catalysts was evaluated in the heterogeneous Fenton degradation of ofloxacin (OFX). In our study, the morphology exhibited a critical impact on the catalytic activity of MnFe2O4. For example, MnFe2O4 nanorods (MnFe2O4-NR) had a higher catalytic activity than MnFe2O4 nanospheres (MnFe2O4-NS) and MnFe2O4 nanocubes (MnFe2O4-NC) in OFX removal and H2O2 decomposition. Notably, the catalytic activity was remarkably enhanced with increasing the relative amount of Mn3+ and Fe2+ species on the surface. Based on the results from quenching experiments and quantitative determination of ?OH radicals, a possible catalytic mechanism of MnFe2O4 was proposed. In addition, the stability and reusability of MnFe2O4-NR was ascertained, as the results suggested that MnFe2O4-NR was a stable and easily separated catalyst for heterogeneous Fenton process.Today energy has become a fundamental need; without energy consumption, no country can survive economically. Along with developed economies, developing countries are struggling more to achieve sustainable economic growth. Therefore, different strategies are being made to develop renewable energy for economic gains. In this line, this study attempts to investigate the impacts of nonrenewable and renewable energy and other socioeconomic factors on CO2 emissions in South Asian countries. The annual data was converted into quarterly data of 1996Q1-2019Q4. The unit root test with structural breaks confirmed mix order of integration and further ARDL approach was applied to know the long- and short-run associations. The long-run association shows that economic growth in Bangladesh, Pakistan, and Sri Lanka is not sustainable. Nepal is achieving economic growth with reducing CO2 emissions. In India, Sri Lanka, and Nepal, institutional quality can play an important role to achieve cleaner production. In Pakistan and Bangladesh, population growth is also lowering CO2 emissions. In India, Sri Lanka, and Nepal, nonrenewable energy usage is contributing to environmental pollution and renewable energy is lowering it. These countries need to enhance the ratio of renewable energy to their industrial production units.Toxic trace elements from both, natural and anthropogenic origin, pose a threat to aquatic environments and marine wildlife due to their long-range transport, bioaccumulative nature, and biomagnification through the food chain. Being long-lived and migratory animals, sea turtles can be exposed to elevated levels of toxic elements, and are therefore considered sentinel species for chemical pollution. https://www.selleckchem.com/TGF-beta.html In this study, concentrations of trace elements (arsenic, cadmium, lead, mercury) were determined in tissues of 46 loggerhead sea turtles (Caretta caretta) stranded along Tyrrhenian and Ionian coasts of Calabria, in Southern Italy, between 2014 and 2020. Curved carapace length (CCL), curved carapace width (CCW), body mass (BM), and sex were determined and the correlations of these parameters with toxic elements concentrations were investigated. During necropsy, kidney, liver, and muscle tissues were collected and the concentration and distribution of metals determined. Muscle tissues showed the lowest toxic element burdens, except for As that showed the highest mean concentrations in this tissue. The kidney was the main accumulation organ for Cd, while similar levels of Hg and Pb were measured in kidney, liver, and muscle tissues. The risk assessment performed for Cd, Hg, and Pb in sea turtles' liver highlighted possible negative effects on sea turtles' health and the need for marine turtle toxicology researches. This is the first study reporting levels and distribution of toxic elements in tissues of Caretta caretta turtles from the Tyrrhenian and Ionian coasts of Calabria.Development of bioenergy will be a key component for meeting increasing energy demands while mitigating global warming. With the intent of identifying current topics of major interest and development of research directions in the field of bioenergy under climate change, we conducted a bibliometric analysis and network analysis from a country perspective based on 3050 articles published since 1999 derived from the Scopus database. The results indicated that USA, UK, and Germany led other countries in terms of number of publications (1006, 366, and 280 articles, respectively) and h-index (greater than 50) in this research area. The USA has also produced a large number of articles in highly respected journals. Compared with developed countries, some developing countries (e.g., China, India, and Brazil) have a larger proportion of publications which are cited less than 10 times and researchers who have academic age of 1 year. The number of publications dealing with some of these research topics coming from developing countries has lagged behind the number of similar publications coming from developed countries.